This invention relates to horizontal deflection amplifiers for cathode ray tubes, and more specifically relates to a horizontal deflection amplifier having utility in producing a high resolution display; i.e., one having a substantially perfect linearity correction.
It is well known that a linear display can straightforwardly be obtained on a spherical shaped cathode ray tube. However, since the advent of so-called "flat-faced" cathode ray tubes, the horizontal and vertical deflection amplifiers must be nonlinear.
Moreover, it has been generally accepted that a high voltage must be applied to the horizontal deflection amplifier in order that the amplifier in turn can supply high voltage signals to the horizontal deflection yoke.
One technique utilized by the prior art was to use class-A amplifiers to produce the deflection current. Although these amplifiers were adequate for a small deflection of currents, they have not found utility with the larger cathode ray tubes because of their low efficiency.
Another technique is to use a high voltage amplifier that has better efficiency than a class-A amplifier. However, this technique requires a large amount of power, most of which is dissipated as heat that can damage other components.
Yet another technique is to use a resonant recovery deflection circuit to correct the output wave form of the amplifier. This technique can produce substantially linear spot deflection on the so called "flat-face" cathode ray tube. However, this technique is complex and requires the application of relatively high voltage. See Electronic Design, Jan. 4, 1973, pages 76-80.
Other techniques are shown in the Hewlett-Packard Company Journal dated Feb. 1968, pp. 2 to 8, tilted "A Precision Solid State Television Picture Monitor" and in the Hewlett-Packard Data Sheets on Raster Display, Model 6947A, dated December, 1970.